<template>
  <view>
    <view class="search-box">
      <uni-search-bar focus :radius="100" @input="input" cancelButton="none"></uni-search-bar>
    </view>
    <!-- 搜索建议列表 -->
    <view class="sugg-list" v-if="kw !== ''">
      <view class="sugg-item" v-for="(item,i) in searchResults" :key='i' @click="goToDetail(item)">
        <view class="sugg-name">
          {{item.goods_name}}
        </view>
        <uni-icons type="forward"></uni-icons>
      </view>
    </view>
    <!-- 搜索历史 -->
    <view class="history-box" v-else>
      <!-- 标题区域 -->
      <view class="history-title">
        <text>搜索历史</text>
        <uni-icons type="trash" @click="clear"></uni-icons>
      </view>
      <!-- 搜索记录区域 -->
      <view class="history-item">
        <uni-tag :text="item" v-for="(item,i) in histories" :key="i" @click="gotoGoodsList(item)"></uni-tag>
      </view>
    </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        //延时器的timerId
        timer: null,
        //搜索关键词
        kw: '',
        //搜索的结果列表
        searchResults: [],
        //搜索历史
        historyList: ['a', 'b', 'c']
      };
    },
    methods: {
      input(e) {
        // console.log(e);
        //清楚timer对应的延时器
        clearTimeout(this.timer)
        //重新启动一个延时器，并把timerId赋值给this.timer
        this.timer = setTimeout(() => {
          //如果500毫秒内没有触发新的输入事件，就为搜索关键词赋值
          this.kw = e
          // console.log(this.kw);
          //根据搜索关键词查询搜索结果列表
          this.getSearchResults()
        }, 500)
      },
      async getSearchResults() {
        //判断搜索关键词是否为空
        if (this.kw === '') return this.searchResults = []
        //搜索关键词不为空，则发起请求
        const {
          data: res
        } = await uni.$http.get(`/goods/qsearch?query=${this.kw}`)
        if (res.meta.status !== 200) return uni.$showMessage()
        this.searchResults = res.message
        this.saveHistoryList()
      },
      goToDetail(item) {
        // console.log(item.goods_id);
        uni.navigateTo({
          url: '/subpkg/good_details/good_details?goods_id=' + item.goods_id
        })
      },
      saveHistoryList(){
        // this.historyList.push(this.kw)
        //1.将Array数组转化为Set对象
        const set = new Set(this.historyList)
        //2.调用Set对象的delete方法，移除对应的元素
        set.delete(this.kw)
        //3.调用Set对象的add方法，向Set中添加元素
        set.add(this.kw)
        //4.将Set对象转化为Array数组
        this.historyList = Array.from(set)
        // console.log(this.historyList);
        //调用uni.setStorageSync(key,value),将搜索历史纪录持久化存储到本地
        uni.setStorageSync('kw',JSON.stringify(this.historyList))
      },
      clear(){
        this.historyList = []
        uni.setStorageSync('kw','[]')
      },
      gotoGoodsList(kw){
        uni.navigateTo({
          url:'/subpkg/good_list/good_list?query=' + kw
        })
      }
    },
    computed:{
      histories(){
        return [...this.historyList].reverse()
      }
    },
    onLoad() {
      this.historyList=JSON.parse(uni.getStorageSync('kw')||'[]')
    }
  }
</script>

<style lang="scss">
  .search-box {
    position: sticky;
    top: 0;
    z-index: 999;
  }

  .sugg-list {
    padding: 0 5px;

    .sugg-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-size: 12px;
      padding: 13px 0;
      border-bottom: 1px solid #C0C4CC;

      .sugg-name {
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        margin-right: 3px;
      }
    }
  }

  .history-box {
    padding: 0 5px;

    .history-title {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 13px;
      height: 40px;
      border-bottom: 1px solid #C0C0C0;
    }

    .uni-tag {
      margin-top: 5px;
      margin-right: 5px;
      display: inline-block;
    }
  }
</style>
